Mongol terror and birthrate constrained militaries

I want to capture the thought before I lose it.  Just saw this and I focused in on "in a birthrate constrained Western military."  Today I see:

Where are the palletized load/unload features and trailer?

It also has to tow things as well as be towable to be a true logistical asset in a birthrate constrained Western military. https://t.co/ajHD6ndSaI

— Trent Telenko (@TrentTelenko) August 17, 2026

Last night I was reading Storm from the East by Robert Marshall and he is discussing the savagery of the Mongols (slaughter of civilian populations) and hypothesizing that it was based in part on their need to inspire terror.  They wanted people to surrender without fighting as the only means of survival.  And this strategy was based on the fact that they were constrained by the small Mongol population.  The terror from mass slaughter was about the only way they could conquer.

When I read it, it also brought to mind the ultimate downfall of the Spartans.  An entire martial culture, individually and collectively among the best trained and effective warriors in history.  And they ultimately fell because there were a "birthrate constrained Western military."

And now virtually all nations, developing and developed are birthrate constrained in ways that are novel in our militaries rapidly shifting to new ways of fighting based on new technologies.  We are seeing some rehearsal of this in the Russia-Ukraine war where Russia is behaving as if it is not birthrate constrained when it is.

But if everyone is becoming increasingly birthrate constrained, does that mean we are at greater risk of contestants resurrecting population elimination as a compensating strategy? Sure hope not but the idea is in my mind now.